One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Modesto should be reviewed to estimate when to plant ageratum.

Planting Calendar for Ageratum

Frost tolerance for ageratum:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Ageratum do not do well in cold weather which means that it is important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Modesto is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant ageratum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your ageratum may not have a chance to fully mature. If you are starting your ageratum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Modesto. You should expect an average low temperature of 25°F in the coldest months of winter.

It's important to remember that USDA zone info for Modesto is an average and the actual date of last frost is different every year. Half of the time in Modesto you get a frost after February 15 so be sure to be ready to protect your ageratum in the event of one of those late frosts.

USDA Zone Info for Modesto

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Modesto

You may be interested in your other planting guides for Modesto.